What is the difference between joint, marginal, and conditional relative frequencies?

The middle cells are the joint frequency numbers. When analyzing data in a two-way frequency table, you will be looking for joint relative frequency, which is the ratio of the frequency in a particular category and the total number of data values. The purple cells on this table are all joint frequency numbers.

The numbers in the column on the very right and on the row on the very bottom are the marginal frequency numbers. When analyzing data in a two-way frequency table, you will be looking for marginal relative frequency, which is the ratio of the sum of the joint relative frequency in a row or column and the total number of data values.

Conditional relative frequency numbers are the ratio of a joint relative frequency and related marginal relative frequency.